The governor's septics bill, part of his legislative package introduced Monday night in Annapolis, tries a new, more complex "tiered" approach. It replaces his controversial proposal last year to ban large housing projects using "onsite sewage disposal," which officials say is a growing source of the nutrient pollution fouling the Chesapeake Bay.

The new plan would take off on Maryland's 15-year-old Smart Growth policies and impose increasingly stringent restrictions on the use of septic systems the farther new housing would be built from existing cities, towns and unincorporated communities. It's an approach recommended by a 28-member task force he appointed to study the issue after legislative leaders shelved his earlier bill.

It remains to be seen if the new proposal will quell the outcry from developers and rural and suburban officials that septic limits will kill growth in their communities.

Instead of banning such development outright, the bill would encourage counties and municipalities to put more growth on centralized sewer systems, while discouraging septic-based construction on farmland and in watershed areas where officials say it's likely to pollute streams and the bay.

State officials point to data showing that septic systems release far more water-fouling nitrogen into ground water and nearby streams than do households connected to properly functioning wastewater treatment plants. Some rural officials dispute that, and accuse the O'Malley administration of waging "war" on their communities by trying to curtail low-density, outlying development through septic limits and "PlanMaryland," a new statewide growth blueprint.

The governor's bill is expected to draw enthusiastic support from environmental activists, though, who have made limiting septic-based development one of their top legislative priorities this year. A coalition of green groups released a poll by OpinionWorks last week indicating that nearly three-quarters of Maryland voters - including 62 percent of those in rural areas that would be most affected - support tightening regulations on septic systems and limiting the number of houses built with them.